PSI - Issue 2_B

ScienceDirect Available online at www.sciencedirect.com Av ilable o line at ww.sciencedire t.com ScienceDirect Structural Integrity Procedia 00 (2016) 000 – 000 Procedia Struc ural Integrity 2 (2016) 2097–21 4 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2016) 000–000

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21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy 21st European Conference on Fracture, ECF21, 20-24 June 2016, Catania, Italy

XV Portuguese Conference on Fracture, PCF 2016, 10-12 February 2016, Paço de Arcos, Portugal Thermo-mechanical modeling of a high pressure turbine blade of an airplane gas turbine engine P. Brandão a , V. Infante b , A.M. Deus c * a Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal b IDMEC, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal c CeFEMA, Department of Mechanical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal Abstract During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation company, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data. Thermographic Image Analysis of Fatigue C ack Prop gation in a High-Alloyed Steel under usage of discrete fourier transformation and rigid body motion compensation Ralf Urbanek*, Jürgen Bär University of the Federal Armed Forces, Institute for Materials Science, 85577 Neubiberg, Germany Abstract To optimize the evaluation of thermographic measurements a lock-in algorithm with motion compensation was developed. Analysis showed that motion of the specimen could be compensated and therefore deformation of stress and temperature fields could be eliminated. Based on the compensated pictures a better identification of the crack tip is possible in both, the E-Mode as well as the D-Mode. Also the resolution for stress measurements especially in regions with high emissive gradients is enhanced. The values of the E- and D-Amplitude evaluation are strongly influenced by the motion compensation. Therefore this correction is essential for quantitative measurements. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of ECF21. Keywords: thermography, rigid motion compensation, discrete fourier transformation 1. Int oduction Lock-in thermography is a common technique for measuring elastic stress fields under cyclic loading since the first thermographic cameras came to market. The elastic stress fields can be evaluated based on temperature fields according to the thermoelastic effect as shown by Brémond (2007). A second field of application is the investigation of dissipative energies via the double frequency method proposed by Sakagami (2005). Previous fatigue experiments by Bär et al. (2015) showed deformed temperature fields assuming this is caused by specimen movement. Sakagami Thermographic Image Analysis of Fatigue Crack Propagation in a High-Alloyed Steel under usage of discrete fourier transformation and rigid b y motion compensation Ralf Urbanek*, Jürgen Bär University of the Federal Armed Forces, Institute for Materials Science, 85577 Neubiberg, Germany Abstract To optimize the evaluation of thermographic measurements a lock-in algorithm with motion compensation was developed. Analysis showed that motion of the specimen co ld be compensated and therefore defor ation of stres and temperature fields coul be eliminated. Based on the compensated pictures a better id ntificati n of the crack tip is possible in both, the E-Mode as well as the D-Mod . Also the resolution for str ss measureme ts espe i lly in regi ns with high emissive gradients is enhanced. The values of the E- and D-Amplitude evaluation are strongly influenced by the motion compensation. Therefore this correction is essential for quantitative measurements. © 2016 The Au ors. Published by El evier B.V. Peer-review under respons bility of the Scientific Committee of ECF21. Keywords: thermography, rigid motion compensation, discrete fourier transformation 1. In rod ction Lock-in thermography is a common technique for measuring elastic stress fields under cyclic loading since the first thermographic cameras came to ark t. The elastic stress fi lds an be evaluate based on temperature fields according to the thermoelastic effect as shown by Brémond (2007). A second field of application is the investigation of dissipative energies via the double frequency method proposed by Sakagami (2005). Previous fatigue experiments by Bär et al. (2015) showed def rmed t mperature fiel s assuming this is c used by specimen movem nt. Sakagami Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://cre tivec mmons.org/licenses/by-nc-nd/4.0/). Peer-review und r responsibility of the Sci ntific Commi tee of ECF21. © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Keywords: High Pressure Turbine Blade; Creep; Finite Element Method; 3D Model; Simulation.

* Corresponding author. Tel.: +351 218419991. E-mail address: amd@tecnico.ulisboa.pt 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review un r responsibility of the Scientific Committee of ECF21. 2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer review under r sponsibility of the Scientific Committee of ECF21. * Corresponding author. Tel.: +49 89 6004 2021; fax: +49 89 6004 3055. E-mail address: ralf.urbanek@unibw.de * Corresponding author. Tel.: +49 89 6004 2021; fax: +49 89 6004 3055. E-mail ad ress: ralf.urbanek@unibw.de

2452-3216 © 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Scientific Committee of PCF 2016. Copyright © 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Peer review under responsibility of the Scientific Committee of ECF21. 10.1016/j.prostr.2016.06.263